68 lines
1.6 KiB
Markdown
68 lines
1.6 KiB
Markdown
---
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id: bd7123c9c450eddfaeb5bdef
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title: Use Bracket Notation to Find the Nth Character in a String
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challengeType: 1
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videoUrl: ''
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localeTitle: 使用括号表示法查找字符串中的第N个字符
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---
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## Description
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<section id="description">您还可以使用<dfn>括号表示法</dfn>来获取字符串中其他位置的字符。请记住，计算机从<code>0</code>开始计数，因此第一个字符实际上是第0个字符。 </section>
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## Instructions
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<section id="instructions">让我们尝试使用括号表示法将<code>thirdLetterOfLastName</code>设置为等于<code>lastName</code>变量的第三个字母。 <strong>暗示</strong> <br>如果卡住，请尝试查看<code>secondLetterOfFirstName</code>变量声明。 </section>
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## Tests
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<section id='tests'>
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```yml
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tests:
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- text: <code>thirdLetterOfLastName</code>变量的值应为<code>v</code> 。
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testString: 'assert(thirdLetterOfLastName === "v", "The <code>thirdLetterOfLastName</code> variable should have the value of <code>v</code>.");'
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- text: 您应该使用括号表示法。
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testString: 'assert(code.match(/thirdLetterOfLastName\s*?=\s*?lastName\[.*?\]/), "You should use bracket notation.");'
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```
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</section>
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## Challenge Seed
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<section id='challengeSeed'>
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<div id='js-seed'>
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```js
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// Example
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var firstName = "Ada";
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var secondLetterOfFirstName = firstName[1];
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// Setup
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var lastName = "Lovelace";
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// Only change code below this line.
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var thirdLetterOfLastName = lastName;
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```
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</div>
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### After Test
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<div id='js-teardown'>
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```js
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console.info('after the test');
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```
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</div>
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</section>
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## Solution
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<section id='solution'>
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```js
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// solution required
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```
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</section>
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